First of all, it isn't this one. Secondly, it's not Google--thank God. Google is just the most popular website. It won't be forever. Wikipedia is certainly a contender. It's really archive.org, also known as the Internet Archive. Go to the page and you'll see their goal in the upper right hand corner of the screen.

Universal access to human knowledge.

That's a tall order. Wikipedia is just trying to be a really good encyclopedia. Google is just trying to be an index for existing publicly available knowledge on the web. The Internet Archive is trying to make all human knowledge available to everyone. It has 1.2 million "texts" (books, essentially), 300,000 audio recordings, 58,000 live concert recordings, and 160,000 "moving pictures" (movies and archival footage). They are the preservers of the world's knowledge, really the essence of humanity. It is the answer to the question: "If you were stuck on a desert island with an internet connection that could only resolve a single domain name, which would it be?" I don't know how many times I've been asked that.